Contagious Chemistry
by workingminds
Summary: After practically being out of the family for three years, Sebastian is now being forced to live with his father, step-mother and step-brother, Blaine, of whom he's only met once. Sebastian Smythe could never forget that boy though, and he's determined to make sure Blaine never forgets him.
1. Chapter 1

**Rating (this chapter)**: PG-13  
**Rating (overall story)**: M/NC-17`  
**Pairing:** Blaine Anderson/Sebastian Smythe  
**Word Count**: 2,344  
**Summary**: After practically being out of the family for three years, Sebastian is now being forced to live with his father, step-mother and step-brother, Blaine, of whom he'd only met once. Sebastian Smythe could never forget that boy though, and he's determined to make sure Blaine never forgets him. (I'm so horrible at summaries)  
**Warnings: **Thoughts of incest.  
**Authors Note**: This was written for rykerstrom because she brought a GKM prompt to my attention.

* * *

Blaine Anderson was fourteen when his mother Rebecca married Andrew Smythe, it was a beautiful service and Blaine was proud to have been a part of such occasion. His mother looked wonderful and he felt so proud, proud of his mother finally escaping his father, proud that she'd done right by her son and proud that she'd found someone to make her the happiest he'd ever seen her. Seeing his mother happy was one of the boy's favourite things, nothing quite compared to this new side he had been lucky enough to see of Rebecca.

His father Robert wasn't the kindest of gentlemen, truth be told, nothing about him was gentle and he was a pathetic excuse for a man, and on top of that, he most certainly didn't approve of Blaine's sexuality. _Faggot _was a common term the boy had to endure in their last year with him. That was a sore subject within the Anderson household. After a messy divorce and Blaine and his mother having to suffer brief counselling after the disaster that was the culminating years of the marriage, things were finally back on track and at last, the really loving family unit he'd always longed for was finally taking place and he was going to try his damned hardest to make sure that he helped keep everyone together. For such a young boy, he sure had a mature head on his shoulders.

With the placement of Andrew into the family, he brought his son along too. Blaine had only met the young boy once and that was at their parents' wedding. He was the same age as Blaine, with thick, soft brown hair and twinkling green eyes that Blaine found easy to trust. Despite his lack of knowledge on the new family member, Blaine was willing to give his _step-brother_ a chance because, well they were practically _brothers _and it seemed forever since he'd seen his biological brother, Cooper_. _ He'd give Sebastian Smythe a chance, and maybe, just maybe they could become friends.

Andrew, Rebecca & Blaine lived together in the Anderson-Smythe household for three years following the wedding, things were calm and the atmosphere was relaxed, Blaine had honestly never felt happier. He had been slightly disappointed when he learned that Sebastian wouldn't be living with them, he wanted the chance to get to know this other boy seeing as this was their last chance before college called upon them and they no longer needed to be living with their parents. But Sebastian lived with his mother in Paris and had been residing there for the previous six years since his parents separated, he didn't visit during holidays and he was barely even recognised in the home with his lack of presence so Blaine had no chance. It was a shame but he quite liked the idea of being an only child, although he didn't enjoy the extensive loneliness that lay in the wake of the business trips that both the adults took together. Blaine had friends, he had quite _ a lot _of friends but none of which he'd invite round to his house to keep him company on the long weekends, so he was left to his own devices, entertaining himself. It helped that he was studious, it was an easy way to pass time and left room for studying so he ensure to keep high A grade standards. But for once, he just wanted to have some fun.

He loved Dalton Academy; it was a private school with a zero tolerance bullying policy (which he was very thankful for) and the students were polite rich kids, it sounded somewhat hellish to an outsider, but attending a school like that was actually a great treat. Blaine was the lead soloist in the _Warblers_, Dalton's all male a cappella choir, he loved to sing and loved to perform, it was the one place where he truly felt himself, he could be Blaine Anderson and not feel like he had to hide parts of himself from the world. He liked being himself.

It was nearing the beginning of summer, Blaine's final week of his junior year to be exact, when Andrew received a call from his now seventeen year old son. Sebastian's mother had fixed herself a new boy toy and wanted to go travelling for a year with him; of course this conflicted with her son's education so she insisted that he returned to Westerville and attended Dalton alongside Blaine for his senior year. Andrew seemed thrilled that he was finally getting the chance to spend time with his son, having not seen him in three years; it was a treat to be reunited with him. Blaine had to suddenly deal with the prospect that he wouldn't be the only child anymore, he'd have a brother again, someone his own age to hang around with but someone who would suddenly impose on his alone time when their parents were away with work. He didn't know how he felt about this, a few years back he would have loved this, this was what he had wanted, but now he was set in his seventeen year old ways and old habits die hard. Blaine didn't like the idea of having to share anything or anyone.

"Seb will be arriving on Thursday so make sure you're ready for him, it's been a long time so please make a good impression. You're a good boy and I wouldn't expect anything less of you, but I really want the pair of you to get along, it would mean a lot." Rebecca informed Blaine, lying across the end of king-sized bed as he was wrapped under his blankets. He adored the nightly chats he had with his mom, it wasn't something he was overly used to but he loved this relationship he had built with her.

"I promise I will mom. I'm hoping to become friends with him, he seemed nice enough when I last saw him so everything will be fine, no worries."

"Okay poppet, I'll leave you to sleep." She removed herself from where she was sprawled out and brushed Blaine's curly hair from his forehead, pressing a tender kiss to it before rubbing his shoulder, "Night B, sleep well sweetheart."

"Night mom, love you." Blaine pulled the covers further up and snuggled down into his pillow to gain some rest.

"I love you too." Rebecca turned out the light and took one last look at the beautiful and loving man her son had turned into. If anyone in this family was proud, it was her.

Thursday afternoon had approached fastly, everyone in disbelief where the past couple of days had vanished. The family had been so busy sorting out one of the guest bedrooms by turning it into a full working bedroom for Sebastian, they hadn't had chance to stop. Blaine's mom and step-dad were picking the other boy up from the airport, leaving him to entertain himself again, just remembering to '_not cause any mess Blaine, promise me? Yes mom._ He was nervous and unsure but oddly excited at the new arrival.

Once Sebastian had arrived and walked through their large open wooden doors to their home, Blaine's excitement suddenly vanished. This ass _smirked _at him. Blaine already wanted to punch him in the face.

"Hey Blaine." He lowly purred in his ear as he passed him in the hallway on the way to the kitchen, Blaine shuddered in response, already creeped out by this newbie living with them._ The term is step-brother, Blaine._

Okay, so that was a strange encounter, not expected at all, but Blaine was still set in giving him the benefit of the doubt. Maybe all the French air went to his head.

A few weeks seemed to pass by without too many hitches, everyone was adjusting to Sebastian _and his unusual attitude, _but overall things weren't too bad. That was until Blaine's mom announced that her and her husband were leaving for the weekend on a lawyers business trip for a case they were both working on, leaving both of the boys home alone. The thought both alarmed and intrigued Blaine, maybe he could work on finding out what Sebastian's motives are with him, his behaviour was unnerving towards him and Blaine wanted to figure it out. Sebastian on the other hand had his sights set on a certain someone, and everyone that knew of Sebastian Smythe, knew he got _exactly _what he wanted. This time would be no exception, this he was sure of.

"_We'll only be gone for the weekend Blaine." Rebecca insisted after Blaine has proposed that he asked Nick Duval (one of his Warbler friends) if he would stay with him and his family for the duration. She understood why Blaine was apprehensive, but Andrew agreed with her that it would do the boys some good to spend time together. Being a family meant tolerating those around you and Blaine had to learn to do this even if he didn't want to._

"_Fine, fine. I'll try and be nice, but don't come back here expecting any miracles, even I'm not__** that**__ good." Blaine answered, as politely as he could muster due to his current frustration and naivety of his mother. He'd either be murdered or molested this weekend and his mother didn't even seem to bat an eyelid._

"_That's all I ask."_

Mr & Mrs Anderson-Smythe had left around 8am, making sure to leave a stern warning to both boys to have no parties and to not burn down the place. Blaine was certain he could stick to his promises; however he wasn't so sure the same could be said forSebastian.

"So Blaine, whatever should we do now that mommy and daddy are away for the weekend?" Sebastian smirked at his step-brother, casually leaning over the breakfast bar with an apple in hand and the other propping his head up.

Blaine couldn't miss the fire in Sebastian eyes, nor the fact that the other boys shirt had risen a good three inches above the waistband of his sweatpants, leaving Blaine a nice eyeful of his step-brothers skin._ Oh hell._

Smythe had noticed the aversion of Blaine's eyes, and quirked his eyebrows, the smirk more present than ever, "Oh Blainers, liking what you see?"

"You're my step-brother Sebastian, don't be disgusting." Blaine sneered; trying to look completely turned off by the prospect of them both engaging in something a little less brotherly. In some respects he was, he just wished the idea totally repulsed him; this would be a lot easier then.

"Like that would ever stop me."

"I should have guessed you'd be into incest." The smaller boy murmured, leaning up into the cupboard to put away the mugs that be just been freshly washed. He didn't care that the leering boys eyes would be all over him, that's Sebastian's problem. Blaine always had liked attention from others, and if this douche was the only one who was going to give it to him, then so be it.

"Incest is the best Blaine. _The best."_

Sebastian left him alone for an hour of which Blaine was thankful, he didn't voice his appreciation but he was still glad of the peace. All he wanted was to relax in the garden with a reading book and a fresh glass of ice tea. It was summer and he was determined to enjoy it in his own way. Downtime was Blaine's favourite thing, whilst all school year he was so immersed in school work, friends and Warbler practice that he felt he had absolutely no time to himself, which was why he always rewarded himself with the summer off. He liked the peace and quiet, he'd grown accustomed to it and now, he really wished he didn't have to share this vacation with another boy that seemed like getting in Blaine's pants over the summer was a good quest to conquer.

As Blaine reclined in the deck chair, placing his book on the floor, he raised his sunglasses over his eyes and lay back. The sun wasn't scorching but it was warm enough for him to enjoy it, all he wanted was a nap since he'd been awake before eight with his mom. The sun dimmed and Blaine began to wonder if he'd missed a few stray clouds in the seamless blue sky, he didn't remember seeing any. He opened his eyes a little, squinting just in case the sun shone brightly again and he didn't have chance to save his eyes. Blaine didn't expect, or didn't want to think, that he would see Sebastian looming over him, an eerie smirk present on his lips that Blaine was slightly attracted to but still intimidated by. Not that he would admit to either of those points.

"What do you want?"

"Let's have some fun, Blainers."

"My name is _Blaine."_

"Now we're family, I think it's time to be more casual and intimate. You seem like the type to enjoy pet names."

Blaine simply rolled his eyes at Sebastian, not being all too sure how to handle someone being quite forward, although he'd never met anyone quite like his step-brother. The taller boy leant over and grabbed hold of the glass sat on the stone flooring and took a large gulp of Blaine's drink, eyes still on him. The smaller boy could visibly see the movement of Sebastian's Adam's apple, bobbing at he let the tea pour down his throat. Anderson was feeling a little warm, and this time he doubted it was because of the burning sun. The boy looming over him licked his lips and wiped his mouth with the back of his hand before handing Blaine his glass back.

"Come and find me if you need me." And with that, he left, leaving poor little Blaine frozen in his chair, thinking of the way Sebastian had looked with his head tipped back and his tongue darting over his lips. Yes, this would be a long weekend. _Hell, _this would be a long summer.


	2. Chapter 2

**Rating (this chapter):** M/NC-17  
**Rating (overall story):** M/NC-17  
**Pairing:** Blaine Anderson/Sebastian Smythe  
**Word Count:** 3, 199  
**Summary:** After practically being out of the family for three years,Sebastian is now being forced to live with his father, step-mother and step-brother, Blaine, of whom he'd only met once. Sebastian Smythe could never forget that boy though, and he's determined to make sure Blaine never forgets him. (I'm so horrible at summaries)  
**Warnings:** Step-brothers engaging in intimacy.  
**Authors Note:** I am dedicating this chapter to the lovely killersmythe. This is taking me so long to write but I wanted to post this one seeing as I've been promising it for about two week. Heavens knows when the next chapter will be though, sorry.

Also, thank you so so so much for your wonderful feedback and follows and favourites and everything you sweet sweet petunias have given me for the first chapter. It means the world.

* * *

Later that afternoon, Blaine found Sebastian again, much to his dismay. He hadn't _meant _to avoid him since the earlier encounter, life just happened to be on Blaine's side. He'd retreated inside in the early afternoon, not finding much peace lying in the garden with the sound of the neighbours spoilt children splashing into the pool and screaming, he'd already read the same page of his book four times. Blaine had trailed back downstairs for a drink and to decide what he could have for dinner, he knew he'd have to consult with the other boy but he sort of hoped he had left the house.

Unfortunately he found Sebastian in the garden, the taller and older boy was lounging in the family pool that had mostly been used by Blaine since the family started living together, however it seemed that now Sebastian was here, he'd become quite the fan. He was resting back against the pool side, his shirt flung onto the chair Blaine was previously sat in and a lollipop head disappearing into the boy's mouth. Blaine shamefully dropping his plastic bottle of water onto the floor, causing enough noise for the other to turn towards him, noticing his step-brothers presence. Blaine had been caught and boy did Sebastian look proud. He pulled the candy from his mouth, licking stripes over it before taking it into his mouth again, his cheeks hollowing slightly as he sucked the blackcurrant flavoured lollipop.

Blaine could feel himself becoming a little flustered as Sebastian kept his eyes trained on him and he repeated the motions with his mouth. The younger boy really hadn't wanted to think about this but now he couldn't stop the ever present thought surrounding his head of his step-brother on his knees, sucking his cock with such haste and eagerness, it was wrong but the image was oh, so right. Blaine's fingers in his hair, nails scraping Sebastian's scalp as he forced himself further, fucking his brothers mouth. He felt dirty, but now he really wanted to try that out, see if Sebastian's mouth was as good as it looked.

He shook his head and bent down to retrieve the bottle from the floor.

"Nice ass Blaine, why don't you bring it over here and we can have some fun."

Blaine rolled his eyes whilst shifting awkwardly to avoid Sebastian seeing the effect he had had on him. His ego really didn't need a boost.

"Tempting, but I'll pass."

"You're missing out; I could show you how good my mouth really is." Shit balls, did Blaine want to tear is clothes off and jump into that pool beside his step-brother, he'd give anything right now for Sebastian to blow him whilst he was immersed in the water. Instead he bit his lip and turned, stalking back off to his room, grabbing his cell phone off the table side.

He called for a take-out, only for him of course, if Sebastian wanted food, he'd have to call himself and learn to act appropriately around family.

Blaine chose to eat alone in his room. He had grinned innocently at his brother who had watched him grab the food in surprise.

Part way into his Char Sui pork, his cell buzzed obnoxiously on his bedside table, breaking his concentration on an old re-run of Saturday Night Live.

_Big Bro._

Blaine furrowed his triangular eyebrows at the name; he didn't remember renaming Cooper's contact. As a matter of a fact he wouldn't name anyone that way, he liked having things written properly and full names used. He was a slight perfectionist.

He clicked to view the message to see who had disturbed him.

_"Blainey, not ordering for me was un-brotherly but come by my room and you can make it up to me ;)"_

Well Blaine hadn't expected that, although now he thought of it, it was painfully obvious. And very Sebastian like. This whole situation had been un-brotherly, and he was sure _making it up _to him would not help his any further. He didn't know how the other boy had managed to take hold of his number but he assumed it was down to the fact he often left his phone lying around the house. That'll teach him.

The curly haired boy shook his head and continued working his way through his dinner. Sebastian would give up sooner or later, he'd _have _to, or so he thought.

As ten pm approached, Sebastian grew impatient, so far his plans to _lure _Blaine in had been failing miserably and he knew it was time to step up his game. If he was going to be genuinely honest, he'd crushed on Blaine back when he was a sweet and innocent fourteen year old, despite only meeting him once; he had pictures from the wedding and memories to fuel the fire. But once he hit mid-teens, Paris and France took its toll on him and his private school friends were keen on parties, drinking and sex. He still didn't forget Blaine though. When Sebastian was told by his mother that she basically didn't want him anymore because she had shacked up with another guy, or boy seeing as he must have been no more than five years older than her son, and told that he was to live with his father and the new family, he very much enjoyed the prospect of finally living under the same roof as Blaine. That was the only upside, he thought. He didn't want to leave his friends behind and this fabulous live of doing whatever the hell he pleased. Although leaving his mother was another upside. The sleazy and cocky approach to flirting with the boy was all he knew, he'd seen guys win his mother over that way and he'd most definitely won more than his fair share that way too. This was why he didn't understand why Blaine hadn't ripped his clothes off yet.

"I just need sex." He muttered aloud to himself, _with Blaine preferably _he added mentally. It had been 2 months since the end of school party in a random students room, the school was terribly lax for a very expensive private school, parties were a given and they didn't care to stop them. Sebastian didn't remember the boy or what he looked like; he just wanted some quick fun before he left for America, knowing he'd be starved of it there. He wondered if this was why he was trying to chase Blaine so much since he had arrived. Sure he'd wanted something with Blaine for three years, but now he couldn't stop the sexual thoughts of him, Sebastian on his knees for Blaine, milking him dry and tonguing his balls, or Blaine on his back with Sebastian's new Dalton tie around Blaine's mouth and his own tie fastening the boys hands to the framework of the new bed Blaine had only assembled a few weeks back. Or maybe Blaine riding him in the pool so every time the four of them spent time in there as a family, he could imagine the way Blaine took his cock in and moaned in delight. Was he thinking of Blaine this way because he needed another way to get off other than his right hand? Or did he want his step-brother that badly that he'd literally do anything?

It was clear to see that Blaine was attracted to Sebastian, even if he did try and make it seem like he wasn't, there was no denying the way his eyes lingered on Sebastian earlier that day in the back yard. But he was too innocent and moral to progress this any further, he'd be mortified if their parents found out about it.

But Sebastian knew he needed a new approach, he needed to go the extra mile and make Blaine aware of just how much he wanted him, no, how much he _needed _him. He made sure his bedroom door was unlocked and his music was turned down before pushing his sweatpants and boxers down to the floor, leaving his shirt on for no reason in particular. Sebastian lay back on the bed and grinned to himself. He pushed his shirt up his abdomen a little with one hand and licked his other before trailing it down until he was grasping his hardening cock; the thought of Blaine being able to walk in right now was so thrilling.

His hand moved rhythmically, finding a steady pace to start before he let his thoughts wander to his step-brother just next door, thinking of his different fantasies surrounding the Warbler, the way he would fuck him into the mattress with just his tongue and he'd make that uptight teen scream in ways he'd never done before.

"B_laine._" He whimpered out, dragging his hand slowly back and forth.

_Fucking Blaine into the shower wall, lips marking the younger boys neck and Blaine's heels digging into the soft flesh of Sebastian's ass, whilst moaning his name as loudly as he could._

"Fuck, _Blaine!" _His cries became louder with each thought, his cock hardening so quickly that he was sure his balls would explode.

_Blaine's hand around his own cock, kneeling in front of Sebastian on his bed, head tipped back as he worked two fingers inside himself._

_"Blaine! Shit – oh fuck!"_

The noises alarmed Blaine, he shot up from his bed as he heard the cry of his name, he may be trying to keep his distance but he'd never forgive himself for turning his back on his step-brother when he needed him. What if a bookcase had fallen on him and he was trapped and was calling for Blaine?

Blaine jumped up and rushed to Sebastian's room, grasping the brass doorknob and turning it, rushing into the room in panic, "Sebastian, are you alr-"

Well. He didn't expect to see _that._He didn'texpect to see the other boy lying there with one hand fisting his shirt and the other fisting his well-endowed 's head was tipped back, burying into his pillow as he screwed his eyes shut tightly. Blaine noticed his brothers face was tinged red in a really fucking beautiful way and he couldn't stop staring, he couldn't stop his eyes trailing over the others' body as he arched and keened into his own hand, hips pushing forward whilst he worked himself to his orgasm.

Sebastian cracked an eye open and smirked, seeing his younger brother _watching him, _so _intently. _His hand rushed and squeezed and he moaned his step-brothers name once more.

Blaine couldn't help the way his name being moaned from Sebastian's lips made his cock harden in his jeans. He couldn't help the way he couldn't take his eyes of him or the pre-come at the tip of Seb's cock. He couldn't help the way he was so turned on by his step-brother.

He knew what he was about to do was wrong, but the teasing had gone on long enough and he needed some physical intimacy with this boy, he needed to feel his hands on him, his _mouth, _be pleasured by him and pleasure him too. Blaine stepped forward until he was crouched next to the bed, not giving himself chance to back out before he pulled on Sebastian's hair and slammed their lips together.

It startled Sebastian who still had his eyes closed but he wasted no time in relishing in the moment he had been waiting for for far too long. The boys grasped the back of each other's heads, pulling them even closer to each other, licking their way around the others mouth.

Blaine briefly broke away from the task at hand as he shifted forward, raising his legs until he was situated comfortably and safely on the bed, practically lying straight over the other boy. Their hips collided; Blaine's clothed cock rubbing against Sebastian's nude one that he himself had managed to pull his hand away from. Sebastian cried out as he felt the drag of Blaine's jeans pull against his leaking cock, the edge of the zipper teasing it causing Sebastian to thrust his hips upwards. Both boys groaned at the feel, Blaine's lips were sucking marks into the taller boys neck, tongue swiping over each mark he created to soothe it. His lips trailed towards the boy's shoulder, tongue dipping down to his collar bone as his teeth sunk in delicately. Blaine loved necks, but he really loved collar bones, the way they protruded from ones upper chest and the way it drove most people crazy, his step-brother being no exception to this.

Blaine wanted to savour every moment of the new found exploration of his step-brothers beautiful body, it was his first time to experience this with him but he knew Sebastian's persistence and need, he'd be pissed if he dragged the foreplay out, and if Blaine was being honest with himself, he had as much self-control as he appeared to. He wanted to rip the remaining shirt from Seb's body and simply devour him until he was arching for Blaine and whimpering and begging him because this time Blaine wanted control, wanted to tease Sebastian for teasing him but his need to blow the taller boy was increasing at a fast pace and he didn't know how much longer he could wait.

Sebastian's whining forced Blaine into cooperating further, working down his torso, making sure to pay attention to his nipples, swirling his tongue around the pink buds, feeling them peak and harden under his wet muscle, Seb's hand back in Blaine's hair as his other tugged his own hair in sexual frustration.

"More Blaine, god _please._" It was then that Blaine kind of adored that cocky and arrogant shit, he knew he was only human, he felt the way everyone else did, he desired another person like we all do and he wanted this attention. Sebastian had his reasons for keeping everyone at arm's length and if he trusted Blaine enough to be closer, then he was going to respect that, respect Seb's choice for wanting Blaine.

The curly haired boy pressed feathery kisses down the length of Seb's torso, licking lightly at his belly button before mouthing at the skin above where Sebastian's waistband would be. He couldn't back out now, he had to go through with this, but he didn't care because he wanted to pleasure him, wanted to make this masked boy finally become himself and be treated the way Blaine deep down knew he deserved. So without further hesitation, he glanced down at Seb's groin, eyeing his cock with delight, feeling nowhere near as embarrassed as he had anticipated, he just wanted this too much to care, wanted to feel his step-brothers cock lying heavy on his tongue as he licked away the pre-come and swallowed him down.

"Blaine, I'm begging you to do something, it hurts so fucking much."

"Shh, it's okay, just relax and I'll help you." Not even a moment later Blaine had one hand round the base of his step-brothers cock and his lips around the head, getting himself used to the sensation after it being so long since had had last done this, it had only been once about a year ago.

"Fuck Blaine." Sebastian managed to force out, his voice strained and shaking, eyes clenched shut and hips stuttering pushing himself further into Blaine eager mouth. Blaine placed a firm hand on one of the other boy hips to push him back down to avoid an embarrassing situation that would lead to a spluttering Blaine.

Both boys eyes met each other, Sebastian giving a silent apology to his step-brother for losing control but Blaine didn't mind, he knew what it was like to be on the receiving end of oral sex and it took strength to stop from forcing yourself further, Sebastian's lack of self-control proved just how well Blaine was performing. Boy did he love to perform.

A less than expert tongue (although he could have fooled Sebastian), ran along the underside of Seb's cock, teasing the vein there causing him to scratch at Blaine's scalp in a really erotic way, heightening the intensity for both of them and Blaine couldn't help but take more of him in as his lips suctioned over Sebastian.

The boy who was arching off the bed felt like he was on fire, he'd wanted Blaine for as long as he could remember, dreamt about how it would feel to have his lips on him, his tongue trailing his body and how he could pleasure Sebastian into crying out, something he rarely did during sex, he just knew it would be different with Blaine. And he was right, he was in heaven, Sebastian wasn't one for using clichés as expressions but he hadn't felt this connected before, he knew deep down that this is what it should feel like to experience these things with the _right _person and god help him he wanted to cry at how right this felt. Sebastian hadn't cried in years.

Eyes remained locked on one another's as Blaine teasingly hummed along Sebastian's cock, cheeks hollowing so he could slide his lips further along him, relishing in the desperate whines and heavy breathing from the most promiscuous person he knew. Blaine figured it was a compliment to have Seb writhing like this. He also quite enjoyed the sounds and the sight of Sebastian's eyes rolling back into his head, the eerie whites of his eyes kind of turning Blaine on because of the cause of it.

Blaine's hand pumped him a little before moving a little more until he could feel the head hit the back of his throat, if it wasn't for the slightest movement that would make him gag, Blaine would have fist pumped the air in pride but that would have also been horribly inappropriate.

"_Shit! Fuck _Blaine! You feel so_…fuck!"_

He worked himself up and down, teasing Sebastian's slit when he pulled back before enveloping his balls into his hot cavern of a mouth, one at a time, sucking them and releasing them like he were eating ice cream from a tablespoon.

Sebastian had no idea how to respond, didn't for once think that this was a side that Blaine had been harbouring away, this sexy and controlling side but he'd be damned if he said he wasn't ecstatic with the discovery. He opted for pulling Blaine's hair harder, feeling the vibration of the younger boys moan around him and called out his name, chanting it as he neared his pending release.

"So close Blaine, god so fucking close."

The orgasm was lived for the first time between Sebastian and Blaine, the brown haired boy writhing and shaking and pawing at Blaine as the shorter one swallowed and gasped and licked until his jaw ached.

Sebastian wondered that if they had sex, maybe he'd realise just how it wasn't the lust that was making him want Blaine, it would be Blaine himself and the feelings he didn't want to admit aloud.

One look between the two step-brothers deciphered that this wasn't just a one-time thing; this connection ran deeper than an incestuous one night stand.


	3. Chapter 3

**Rating (this chapter): **PG-13  
**Rating (overall story):** M/NC-17  
**Pairing:** Blaine Anderson/Sebastian Smythe  
**Word Count:** 2,000+  
**Summary:** After practically being out of the family for three years,Sebastian is now being forced to live with his father, step-mother and step-brother, Blaine, of whom he'd only met once. Sebastian Smythe could never forget that boy though, and he's determined to make sure Blaine never forgets him. (I'm so horrible at summaries)  
**Warnings:** Step-brother!feelings  
**Authors Note:** I'm so so sorry this took so long, I have no excuse other than I've been working so much and I started college again last week. Hopefully I won't be that long again. This isn't a smutty chapter, it's just full of feelings!Seblaine.

Thank you so so much for all of your support so far, it means the world to me.

Love you all.

* * *

If there was one thing Blaine Anderson wasn't expecting, besides engaging in sexual activities with his step-brother, it was waking up next to said step-brother. Sebastian's arms were loosely wrapped around Blaine's torso and his chin resting atop the smaller boys head as he inhaled and exhaled shallowly, light snores escaping them both. Neither had anticipated spending the night curled up in Sebastian's bed, Blaine had decided that he would retreat to his own bed once he had come down from his post-orgasm haze, but the heat radiating from a sweating and ever-so-inviting Sebastian, had lulled Blaine into a resting and calming sleep before he even had a chance to discuss what the hell had just happened. Although that was a conversation Blaine was very anxious to participate in.

The rain was beating down on the large window opposite the queen sized bed, bleak skylight travelling in through the gap of the heavy curtains draped over the window. It woke the youngest family member, left him feeling slightly confused for a moment before realisation flooded him. Blaine had spent the best part of the last half hour listening to the pouring rain running down the drainpipes, beating puddles in the gutter and tapping at the windows, feeling completely calm. The outside world was wet and cold and drowned, but Blaine was warm and dry and so completely content with the warmth of another boy beneath him. He'd always adored the rain on lazy days that he was fortunate to spend at home, he'd fallen in love with the sounds, the feeling's he'd felt and how he felt safe in his own home. He liked being at peace with the world. Blaine was always so busy and pre-occupied with this, that and the other, that this was exactly where he _should _be. It sure felt that way to him anyway.

Blaine couldn't stop the way his eyes lingered on the other boy, admiring his beauty and charm when he wasn't awake to show off this giant bravado. The younger brother enjoyed how natural he seemed when sleeping, it was like a completely different person because he wasn't showing off, or lingering at Blaine, he was the one being watched. Blaine's index finger lazily traced patterns on the middle of Seb's chest, not in any attempt to wake him; more just for his own comfort and living in the moment that he wasn't sure would last beyond the next twenty minutes or so. He couldn't refrain from pressing small kisses across his taut stomach, it was alluring to Blaine's eye and he just wanted to constantly touch Sebastian, not just in a sexual way but in admiring way, almost like if he wasn't physically touching Seb, he wouldn't really believe he was there.

With a simple brush of his thumb over one of Sebastian's nipples, the older boy groaned, waking up a little startled by the sensations he was feeling. His eyes fluttered awake and he wriggled, knocking Blaine's hands from his body before he stretched. Then Sebastian's eyes settled on Blaine who was looking at him expectedly, wondering what their next move would be.

"What are you doing here, Blaine?"

Blaine's eyebrows furrowed, "What do you mean? I slept here."

Sebastian looked terribly confused, wondering why in the world Blaine had slept he- oh. Oh of course, _last night._

His reaction reassured Blaine that everything did happen last night and he hadn't accidentally slept walked his way into bed and dreamt about what he would like to do Sebastian as opposed to actually living it.

"Oh, yeah, last night. Well I think you should leave now Blaine, you were fun and all but it's time you left."

Blaine's heart stopped, he couldn't believe he was being pushed out after sex like some lousy one night stand. He knew Sebastian could stoop low, but he didn't think he was heartless, he genuinely believed something has changed between them last night.

"You- you want me to _leave_?"

"I said that didn't I?"

"I just thought-"

"You thought you could blow me and then everything would be different and we'd start dating and live happily ever after?"

Blaine hated how blatantly Sebastian was mocking him, mocking his newfound attraction and hurting his feelings all at once. Was it so wrong for him to want something from the other boy? Well, yes, Blaine thought there clearly was for this reaction. Maybe Seb wanted to quick fun with the nearest available willing participant. Too bad Blaine fell for it.

"I thought you felt something but I should have known you'd be an asshole about it."

That shouldn't have hurt Seb but it did anyway, he knew he was being unreasonable and unfair to Blaine. He wasn't heartless; not really, he didn't want to upset this beautiful boy before him, who was curling in on himself in discomfort. Seb hated seeing the pain flash through his eyes but he had to be firm, he was being responsible for once and he loved his father, he was beyond happy that he was all loved up with his new wife. He didn't want to be held responsible for breaking that up so soon because he couldn't keep his dick in his pants.

"You should go Blaine." His eyes were pleading with the other boys, hoping he'd just leave and not question it because he didn't want to show that he cared, that would only make this harder. With a scowl, Blaine stormed from the room leaving Seb with his head in his hands feeling pretty terrible.

Blaine didn't cry about it, just as much as Sebastian _didn't _smash his bedroom mirror with his boot.

The rest of the day was a complete washout; both boys locked themselves in their room, listening out for the other so they could avoid having an awkward and uncomfortable conversation on the stairs when fetching food. Each lingered on the sounds of the others footsteps padding across the landing and to their respective bedrooms.

The rain was still bouncing and the weather was stormy, rumbles of thunder reverberating through the house. Right now Sebastian wished he hadn't told Blaine to leave him alone; he despised thunder and would give anything for Blaine to take him in his arms and hold him until it passed. Not that anyone had ever really done that for him before, but he just knew it was something Blaine would love to do, just knew the younger boy would rake his hands through his hair, scratching at the scalp and soothing him. Seb couldn't resist the whimper that emitted from his mouth, god did he want that.

He was stewing for all of five minutes before he gave up the waging war inside his pounding head and slipped his feet into his slippers before lightly walking the short distance to Blaine's bedroom. He was going to apologise and explain and lay his heart on his sleeve because surely if Blaine still wanted him, then his father would be happy with whoever he found happiness with, and if that happened to be his step-brother then so be it.

"Blaine?" He asked lightly, gently raising his knuckles to the wooden door.

"Go away Sebastian."

"Please? Let me talk."

"I think you said quite enough this morning." Seb could hear the strain in Blaine's voice and he responded quietly.

"Blaine, it's fucking thundering right now and I need to talk with you. For once I'm actually begging for you to let me in." Silence followed that statement, Sebastian assumed he'd lost and would actually have to retreat to his bedroom rejected, not like he didn't deserve it. He just didn't like showing his feelings for nothing. Just as he was about to turn to walk away, he heard Blaine's footsteps shuffling around his room and the lock on the door opening. He raised his head to meet Blaine's slightly swollen eyes which made him look all the more endearing to Sebastian but making him feel a little heartbroken all the same. Blaine pushed off from the door, leaving it ajar for Seb to follow him in as he sat against the headrest of his bed and stared straight back at the Friends re-runs he was watching.

"I uh-I hate storms." Sebastian spoke, scratching the back of his neck and feeling a little lame as he stood awkwardly in the middle of Blaine's room. The younger moved his feet for the other to sit down.

"I love them." Blaine didn't bother breaking eye contact with the television; he did however see Seb out the corner of his eye sit down as he felt the dip in the bed.

"I've been afraid of thunder since I was little, I used to hide under my duvet every time because I thought it was a sign that I had been naughty and I was going to be punished. That's what my mom always told me."

Blaine hated that his mother had led her child to believe that but he continued on with his nonchalance, secretly wanting to hold other boy, "Why are you telling me this, Sebastian?"

He shrugged, "I don't know, I guess I want to show you that I'm only human and I do have feelings. The person you dealt with this morning was an asshole, sure, but he was an asshole who was trying to save his family. He was so scared of fucking up the perfect family he'd always longed for. That boy didn't want to ruin another boy nor ruin their parents' marriage."

Blaine was quick to realise that he hadn't even taken Andrew and Rebecca into consideration when last night occurred. Now he felt shitty._ He _was supposed to be the good and caring child, not this brat who had pretty much grown up in France who didn't care about anyone but himself. He'd been blinded by this charming boy who so evidently wanted him, that he didn't even think about what would happen if they found out. Would Sebastian be shipped back to his god-awful mother if they found out?

"I guess I hadn't thought about that."

"I had to, god Blaine, last night was not a mistake in the slightest but I was trying to be rational and if pushing you away like that would save our family then that's what I wanted."

"You didn't have to be so harsh though." Sebastian hated Blaine's kicked puppy face despite how adorable he looked. Never had he looked so young or naïve.

"I know, it's just what I'm used to. I'm sorry," He leant forward and took one of Blaine's hands in his own, "I was unfair and that's why I wanted to apologise and make it up to you."

"Why the change of heart then? Surely you still want our parent's to be together."

"Of course I do, I've never seen my father so happy and as long as they're together, I can stay here. But, I couldn't lie to myself and pretend I wouldn't be hurting if I cut you off. I've liked you for four years and I've wanted this for so long, I can't give up on that if you're willing to have me."

"You have?"

"Of course I have, the first time I met you I was drawn in, but then I went back to Paris and things turned to shit. I was shipped off to boarding school where I met lots of boys, fell in and out of love within my first year way too many times to remember and then I gave up. I gave myself to anyone who wanted me. That's probably why I tried so hard with you when I first got here. I wanted to impress you but I just came off as creepy and sleazy, I see that now."

"You were pretty sleazy." Blaine lightly laughed, he adored how open Sebastian was being with him, he was very much a guarded person but to have broken down his walls for him felt amazing.

"I just want you to know that I'm not trying to get in your pants because I think I can, I just want to be around you because you make me feel worth something, it's nothing I've felt before and I'm sorry if that scares you."

"It doesn't. It thrills me." He runs his thumb over one of Seb's hand, reassuring him before speaking again, "Can you kiss me? Just so this time I know it actually means something?"

Seb raised his hand to Blaine's face, staring at him adoringly, admiring his beauty before leaning forward and softly pressing his lips to the other boys. Blaine's hands came up to rest on Sebastian's hand, gripping him closer and parting his lips, gently pushing his tongue into Seb's mouth. The older boy couldn't help but moan at how right this all felt, revelling in the feeling of Blaine's tongue rubbing his own. Blaine leant forward a little more, nudging Sebastian to lie back on his bed where he lay half on top of him, continuously kissing his lips. The pair broke for a breath and beamed at each other. They were both so happy that they didn't even realise that the storm had passed. Maybe everything would be alright afterall.


	4. Chapter 4

**Title:** Contagious Chemistry  
**Rating (this chapter)**: NC-17/M  
**Rating (overall story)**: NC-17/M  
**Pairing:** Blaine Anderson/Sebastian Smythe  
**Word Count: **1,118  
**Summary:** After practically being out of the family for three years, Sebastian is now being forced to live with his father, step-mother and step-brother, Blaine, of whom he's only met once. Sebastian Smythe could never forget that boy though, and he's determined to make sure Blaine never _forgets_ him. _(I'm so horrible at summaries)  
_**Warnings:** Handjobs, kitchen!sex  
**Authors Note:**As always, this is written for rykerstrom. As always, this has not been beta'd. Maybe I should invest in one.

I'm sorry to those who have been waiting for this, it's a bit of a let down considering it's taken months and it's quite sort, hopefully I'll get chance to write over the next week so you'll have one before christmas :)

"As nice as it is lying here and basking in this moment, my stomach rumbling is a major sign that we really ought to eat." Blaine laughed at the rumbling disturbing their silence. The boys had been lying there for over an hour, lazily kissing, holding each other, legs tangling, adoring the feel of another person beside them.

"I guess you're right." Seb sighed, burying his nose in the crook of Blaine's neck, lips pressing to the exposed skin, tongue peeking out to wet the area, "just promise me that we can do a whole lot more of this when we finish?"

"Deal." Blaine replies, firmly kissing Seb, grazing his tongue before pulling away and smirking at the boy now beneath him. He retreated from the bed and swayed to the bedroom door, throwing a cheeky smile over his shoulder and left.

Sebastian shook his head and smiled. He couldn't believe how quickly everything had changed. He hadn't anticipated Blaine giving in so easily and now he had, Seb was thrown off course. After Sebastian's history and usual attitude, he didn't expect to have such an attachment; he fully assumed he'd continue being this cocky and self-assured asshole that everyone knew. But the effect of the Anderson boy had thrown him for six in a matter of hours.

Running his hand over his face, he smiled again, happy with where he was at. Happy to be loved. Happy to be cared for. He dragged himself from Blaine's bed and pulled on a pair of Blaine's rare socks that were barely worn and joined him in the kitchen to try and tempt him back to bed.

Entering the kitchen, Bas spotted Blaine crouched down in front of the freezer, scouring for something simple and quick to make before he starved half to death. He knelt behind him and trailed small kisses down his neck. Blaine arched his back and elongated his neck to expose more for Seb to press his lips to. Both wanted to cry and laugh at the simple gesture.

"Seb," Blaine whined, trying to contain a grin and shrugging the other boy off, "I need to find some food."

"Mmm, don't wanna." Seb wrapped his arms around Blaine's torso and the curly haired boy leant back into him, settling between his legs and tipping his head back on the others shoulder.

"This is nice." The younger boy purred, letting his eyes close momentarily before they shot open again at his stomach breaking the moment once again.

"Fine, you can have food."

Blaine pecked Seb's lips before standing and lazily sauntering over the cupboard, hips swaying for his step-brothers benefit. Sebastian lightly laughed before rubbing his hand over his face and lying down on the floor.

"Are you satisfied now you've eaten?" Sebastian smiled, genuinely smiling for the first time in years because this boy opposite him gave him a reason to, a reason to feel alive. The pair were sat opposite each other on the breakfast bar, Seb leaning on his hand as he watched Blaine lean back, rubbing his full stomach.

"Much better." Blaine couldn't stop the smile forming as he watched Sebastian watching him, he didn't expect to feel like this when it was only six months ago he split from the boy he was so sure he'd spend eternity with. He could see the agitation in Seb's posture, tapping his leg against his stool impatiently, causing Blaine to smile wider.

"What?" Suddenly Sebastian felt self-conscious, wondering _why the fuck_ Blaine was looking at him so inanely and wondering _what the fuck_ he'd done for that look in 0.3 seconds.

"You're antsy, Sebastian." Seb playfully rolled his eyes and stood up, his stool screeching across the slated floor causing Blaine to wince. "Where are you going?"

Instead of answering, Sebastian pulled Blaine from his stool, yanking him close and pressing him roughly against the kitchen wall.

"Kitchen wall sex?"

"It's even a first for me." Both boys immediately leapt forward, crushing their lips together and wasting no time whatsoever, afterall they only had about forty-six hours until their parents arrived home. Sebastian pulled on Blaine's hair causing the smaller boy to lowly groan in Seb's mouth which was definitely a pleasant surprise for him. The taller boy made a mental note to do that more often. Definitely if that reaction was guaranteed. Both boys' hips bucked into one another's, friction turning their erections harder in their sweatpants and panting into their partners mouths. Sebastian couldn't refrain from letting his palm drift to rub over the front of Blaine's pants, desperate to push his hand inside to grasp the younger boys cock.

"Do it Sebastian." He didn't need to be told twice, within seconds he had Blaine's sweats around his ankles and a firm hand grasping Anderson's cock. Sebastian still couldn't believe this was finally happening, sure Blaine blew him last night, but this was different because virtually all of his one night stands, he had pictured Blaine instead, especially after stalking him online and finding how he looked as he had grown older. He couldn't grasp the fact he was sharing this with Blaine.

"Blaine – fuck, you're so beautiful."

"Shit Bas, more – please _– more_." Sebastian was pumping him agonisingly slow before speeding his actions up more dramatically, Blaine arching and keening and _fucking_ himself on Bas' hand, hips slamming forward in desperation. Sebastian had never seen someone so _needy_ and _desperate _and _wanting_ as the boy in front of him. It was delicious. Blaine was on the verge of tears and Bas jerked him with one hand and fondled his balls in the other, pinching and squeezing the skin as they drew unbearably tight. They knew it would only be seconds away now.

"S-so close, S-Seb." Blaine eyes were clenched shut, his head tightly buried in Sebastian's neck and his teeth sinking into the flesh where neck meets shoulder.

"Let go." And he did, the Anderson boy couldn't contain it any longer, he came hard and fast, whimpering and whining and screaming his step-brothers name in sheer pleasure. Never had he come so hard.

"H-holy shit." Within seconds, Blaine had a hand around Sebastian and was jerking him until their come mixed and slithered down their bodies, droplets hitting the kitchen tiles in small splashes.

Neither could stop the smiles, the breathy laughs or the wet sounds of open mouthed kisses. Tongues licking, teeth biting, lips reddening. It was perfect. It was blissful.

"Care to join me in the bedroom?" Blaine asked, honey coloured orbs, staring under long luscious lashes at the lustful looking boy.

No answer was heard as the taller boy lifted Blaine around his waist and carried him back to bed.


End file.
